Medical forceps

ABSTRACT

The invention relates to a medical forceps with a tubular outer shank on whose distal end there is formed a forceps jaw with two jaw parts, wherein the two jaw parts in each case at two sides opposite one another are rotatably mounted on the outer shank, with a tubular inner shank for actuating the jaw parts, which is displaceably arranged in the inside of the outer shank in its longitudinal direction, wherein the inner shank is coupled via two lever systems to the two jaw parts for their actuation and in each case one of the lever systems is linked on the two jaw parts on one of the two sides opposite one another.

BACKGROUND OF THE INVENTION

[0001] The invention relates to a medical forceps.

[0002] There are known medical forceps which comprise a hollow shank into which for example an optical system is applied. From DE 44 44 403 Al there is for example known a medical forceps which comprises a hollow shank on whose end there is arranged a pivotable forceps jaw part. The opening and closing of the forceps jaw part is effected via an inner shank longitudinally movable in the inside of the shank. This inner shank engages centrally on the upper side of the forceps jaw part. The forceps jaw part in the lower region on two sides is rotatably linked onto the outer shank. By way of displacing the inner shank in the longitudinal region of the forceps shank the point of engagement of the inner shank on the forceps jaw part is radially pivoted about the rotation point of the forceps jaw part and in this manner the forceps jaw is opened or closed. In the opened condition this has the effect that a rear end of the forceps jaw part pivots into the inside of the shank. By way of this, when the forceps is open, the field of view for optics arranged in the inside of the inner shank is very greatly limited.

BRIEF SUMMARY OF THE INVENTION

[0003] It is the object of the invention to provide a medical forceps with which a large forceps force may be created and which permits as large as possible field of view for optics arranged in the inside of the forceps shank.

[0004] This object is achieved by a medical forceps with the features specified in claim 1. Preferred embodiment forms result from the dependent claims.

[0005] The medical forceps according to the invention comprises a tubular outer shank on whose distal end there is formed a forceps jaw with two jaw parts. The tubular outer shank preferably has a circular cross section and the two jaw parts together likewise preferably form a circular cross section of essentially the same diameter as the outer shank. The two jaw parts are in each case rotatably mounted on the outer shank on two opposite sides, i.e. preferably two sides lying diametrically opposite one another. Furthermore in the tubular outer shank there is arranged a tubular inner shank for actuating the jaw parts. The tubular inner shank extends in the longitudinal direction parallel to the outer shank. At the same time the tubular inner shank preferably has an outer contour which is designed corresponding to the inner contour of the outer shank so that the inner shank is slidingly guided in the inside of the outer shank. The inner shank is coupled to the two jaw parts for their actuation via two lever systems. The lever systems convert the movement of the inner shank in the longitudinal direction into a pivoting or rotational movement of the two jaw parts. For this in each case one of the lever systems is linked on the jaw part on one of the two sides lying opposite one another. This means the lever systems for opening and closing the jaw parts are arranged on the same side of the forceps on which also the mountings for the pivotable jaw parts are provided. The mounting and actuation elements for the jaw parts are thus extremely compact and arranged tightly next to one another. This permits the mounting and actuation elements for the jaw parts to be designed slimline and compactly. Since the lever systems are arranged laterally on the forceps it is not necessary for the elements of the jaw parts or the lever systems to project into the inside of the outer or inner shank on opening the forceps jaw parts. This means the inner space of the inner shank as well as the region mounted in front of the opening of the inner shank on its distal end may be kept free also when the forceps jaw is opened, in order to ensure a largest possible field of view for optics applied into the inner shank. By way of the linkage on both sides or the engagement of the lever system on each jaw part on both sides one may furthermore transmit a large force onto the jaw parts so that a large forceps force may be made available for example for separating tissue parts. The arrangement of two jaw parts permits a very large angle of opening of the jaw part, by which means on the one hand the gripping of difficultly accessible or large tissue parts is favored and on the other hand the field of view through the opened forceps jaw is very large.

[0006] Preferably the two jaw parts in each case on each of the two sides opposite one another, in the longitudinal direction of the outer and inner shank comprise a proximally extending linkage lever which in each case is coupled to the inner shank via one of the two lever systems. The jaw part extends in the distal direction of the forceps proceeding from a mounting point on which the jaw parts are mounted on the outer shank. The linkage lever extends proceeding from the mounting point in the opposite direction, i.e. in the proximal direction. The linkage levers are preferably designed as one piece with the associated jaw parts. For opening the jaw parts the associated linkage lever must therefore be pivoted in the same rotational direction as the jaw parts. For this the linkage levers are connected to the inner shank via the lever systems. The lever systems set the linear movement of the inner shank in its longitudinal direction into a pivoting movement of the linkage lever which for its part pivot out the two jaw parts. These two jaw parts with the associated linkage levers thus have a course of movement similar to a scissors.

[0007] Preferably the linkage levers and the lever system are arranged lying radially further outside than the inner circumference of the inner shank. Such an arrangement has the effect that the smallest inner diameter of the whole forceps which is available is defined by the inner diameter of the inner shank. Thus optics may be introduced through the inside of the inner shank up to the distal end of the forceps and thus be brought very close to the distal end of the forceps jaw. Furthermore the field of view of the optics is not compromised by components of the actuation mechanism for the jaw parts, which lie further inside. Thus one may create a very large field of view which ensures good observation possibilities on applying the forceps.

[0008] The two jaw parts on the two sides opposite one another are preferably mounted in each case on a common rotational point on the outer shank. This arrangement reduces the number of the required rotational points and effects favorable lever ratios which permit a large force transmissions. Furthermore this arrangement allows the forceps jaw to be able to be completely closed so that the two jaw parts with the side edges facing one another bear on one another.

[0009] The linkage levers in each case are usefully connected to the inner shank via a transmission lever. These transmission levers with a linear movement of the inner shank on the linkage levers produce a torque about their point of rotation which leads to the pivoting of the linkage levers and thus of the jaw parts connected thereto, for opening and closing the forceps jaw.

[0010] The transmission levers preferably on a first end are in each case rotatably connected to the linkage lever and on a second end rotatably connected to the inner shank. In this manner the linear movement of the inner shank may be converted into a pivoting or rotational movement of the linkage lever and of the jaw part connected thereto. With a linear movement of the inner shank the respective transmission lever pulls or pushes the associated linkage lever in a direction tangential to its point of rotation so that this is pivoted about the point of rotation. On pivoting the linkage lever its force engagement point at which the transmission lever engages is displaced. This displacement may be compensated on account of the rotatable linking of the transmission lever on the linkage lever and the inner shank.

[0011] Preferably, on the opposite sides of the inner shank in each case two transmission levers are connected to the inner shank in a common rotation or linkage point. This arrangement reduces the number of required rotational or linkage connections, by which means the assembly is simplified. Furthermore one ensures a symmetrical actuation or movement of the transmission lever and thus also of the jaw parts. A uniform and reliable force transmission may therefore be ensured. According to the movement direction of the inner shank the transmission levers push or pull on the linkage levers, by which means the jaw parts are pivoted. At the same time the push or pull direction of the transmission levers runs at an angle to the longitudinal axis of the inner shank.

[0012] At the distal end of the inner shank there is preferably formed at least one radially outwardly projecting projection which engages into a corresponding recess at the distal end of the outer shank, wherein the recess in the longitudinal direction of the outer and of the inner shank has a greater extension than the projection. This arrangement of projection and recess forms a linear guide of the inner shank in the outer shank in its longitudinal direction. Furthermore on account of the play which is defined by the length difference of the outer and inner shank one defines a limitation for the maximum linear movement of the inner shank in the outer shank. Such a limitation, on account of the coupling of the inner shank and jaw parts thus likewise leads to a limitation of the angle of opening of the jaw parts. Additionally this linear guiding of the inner shank in the outer shank ensures that the inner shank correspondingly co-rotates with a rotation of the outer shank about its longitudinal axis. In this manner it is possible to rotatably arrange the outer and inner shank on the forceps grip, wherein the whole jaw region of the forceps, i.e. the distal end of the forceps with the forceps jaw may be very simply rotated about its longitudinal axis by rotating the outer shank.

[0013] On the inner shank it is further preferred to form a projection on each of the sides opposite one another and for the outer shank to comprise two corresponding recesses into which the projections engage. In this manner a precise guiding of the inner shank in the outer shank is achieved. Furthermore a secure force transmission when rotating the outer shank onto the inner shank may be ensured. By way of the arrangement of the recess and projection on the two sides opposite one another on which the mounting points as well as the lever systems are provided for pivoting the jaw parts, an extremely compact and slim arrangement of all guide or mounting and actuation elements is achieved. In this manner a largest possible free space in the inside of the forceps in its distal end region is created. Furthermore it is possible to provide openings or recesses in the outer and inner shank in its distal end region. By way of these measures the field of view for optics arranged in the inside of the forceps may be increased.

[0014] Preferably the linkage levers of the two jaw parts on each of the sides opposite one another are designed such that the linkage lever of a first jaw part is formed radially lying further inwards than the linkage lever of the second jaw part. This means that the two linkage levers are arranged lying over one another or overlapping one another in the radial direction, i.e. in the direction which connects the two opposite sides transverse to the longitudinal direction of the outer and inner shank. This scissor-like arrangement of the levers permits an extremely slim and compact construction of the lever system for actuating the jaw parts.

[0015] The two actuation levers on each of the two sides opposite one another are in each case further preferably arranged lying radially over one another. The arrangement is preferably designed such that that transmission lever which is connected to the linkage lever of the first jaw part lies in a plane with the linkage lever of the second jaw part whilst that transmission lever which is connected to the linkage lever of the second jaw part lies in a plane with the linkage lever of the first jaw part. The linkage and transmission levers are thus arranged lying over one another or overlapping, displaced to one another. Thus a parallelogram-like lever system is created by the linkage and transmission levers for the two jaw parts on each of the two sides opposite one another. This arrangement is extremely compact and may further transmit a large force from the inner shank onto the jaw parts so that these may exert a large closing force which favors a separation of tissue parts.

[0016] Furthermore the linkage levers of the two jaw parts preferably on each of the two sides lying opposite one another are designed such that seen in the longitudinal direction of the outer shank in the closed condition of the forceps jaw, the free end of the linkage lever of the first jaw part extends in the extension of the second jaw part and the free end of the linkage lever of the second jaw part extends in the extension of the first jaw part. This means that with respect to the longitudinal axis of the inner and outer shank the linkage levers are bent at an angle or stepped to the longitudinal axis of the respective jaw part. Preferably the linkage lever extends parallel displaced to the longitudinal direction of the associated jaw part wherein the rotation point of the jaw part lies preferably essentially in the middle between the longitudinal axis of the linkage lever and the longitudinal axis of the jaw part. At the same time the longitudinal axis of the linkage lever and the longitudinal axis of the jaw part run essentially parallel to the longitudinal axis of the outer and inner shank. The longitudinal axis of the inner shank preferably lies essentially on a plane with the two rotation points on which the two jaw parts are linked on the outer shank. The two rotation points on which the transmission levers are pivotably mounted on the inner shank preferably lie in the plane of the longitudinal axis of the inner shank and of the points of rotation of the jaw parts. The end regions of the linkage levers which are connected to the transmission levers preferably lie outside this plane. In this manner it is ensured that the longitudinal direction of the transmission levers, i.e. the direction of the force transmitted by the transmission lever always runs at an angle to the longitudinal axis of the associated linkage lever and of the inner shank. In this manner one may ensure that in each position of the forceps a secure pivoting of the jaw parts is possible and that the forceps may not jam.

[0017] In a preferred embodiment form a hole may be formed in at least one of the two jaw parts. Such a hole permits one to look through the forceps jaw from the inside of the forceps or the inner shank also when the forceps jaw is closed. In this manner the positioning of the forceps with an operation may also be simplified when the forceps jaw is closed. The hole is preferably arranged in the middle of the jaw part distanced from its outer or cutting edge so that furthermore a secure grip or a reliable cutting or separation of tissue by the forceps is ensured.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Hereinafter the invention is described by way of example by way of the attached figures. There are shown in:

[0019]FIG. 1 a sectional view of the medical forceps according to the invention;

[0020]FIG. 2 a detailed view of the forceps jaw in the closed condition,

[0021]FIG. 3 a detailed view of the forceps jaw in the opened condition;

[0022]FIG. 4 an enlarged schematic sectional view of the forceps jaw in the closed condition,

[0023]FIG. 5 a view of the forceps jaw in the direction of the arrows A in FIG. 4,

[0024]FIG. 6 a view of the forceps jaw according to FIG. 4 in the opened condition,

[0025]FIG. 7 a detailed view of a forceps jaw in a plan view,

[0026]FIG. 8 a section view of a jaw part along the line 1-1 in FIG. 7, and

[0027]FIG. 9 a detailed view of a deflection lever.

DETAILED DESCRIPTION OF THE INVENTION

[0028]FIG. 1 shows in a sectioned view the total view of the forceps according to the invention. The medical forceps comprises a forceps shank 2 at whose distal end there is arranged a forceps jaw 4 and at whose proximal end there is arranged a forceps handle 6. The forceps shank 2 consists of an outer shank 8 and of an inner shank 10 arranged in the inside of the outer shank. The outer shank 8 and the inner shank 10 are tubular, in particular formed with a circular cross section. At the same time the inner shank 10 has an outer diameter which essentially corresponds to the inner diameter of the outer shank 8. This permits the inner shank 10 to be guided in the outer shank 8 in a fitting manner and essentially free of play or with little play. The optics 12 extend from the proximal end of the forceps into the inner shank 10 and through this preferably up to the distal end 14 of the inner shank 10 in order to permit an observation of the region surrounding the forceps jaw 4 or of the region situated in front of the forceps jaw 4 during the operation.

[0029] At the proximal end of the forceps there is provided a forceps housing 16 proceeding from which the forceps shank 2 extends in the distal direction. In the forceps housing 16 at the distal end there is arranged a rotatable hand wheel 11 which is rigidly connected to the outer shank 8. The outer shank 8 may be rotated about its longitudinal axis by way of rotating the hand wheel 11. At the proximal end of the forceps housing 16 there is formed a cone receiver 18 in which the optics 12 may be releasably fixed. Furthermore a sliding sleeve 20 is arranged in the inside of the forceps housing 16. The sliding sleeve 20 is displaceable in the forceps housing 16 in the longitudinal direction of the outer shank 8 and of the inner shank 10. The sliding sleeve 20 is connected to the movable handle part 22 for actuating the sliding sleeve 20. The movable handle part 22 is pivotably mounted on the stationary handle part 24. The rigid handle part 24 is connected to the forceps housing 16. The sliding sleeve 20 is displaced in the axial direction, i.e. in the longitudinal direction of the forceps shank 2 in the forceps housing 16 by way of pivoting the movable handle part 22. The sliding sleeve 20 is rigidly connected to the inner shank 10. Thus the inner shank 10 is displaced in its longitudinal direction, i.e. in the axial direction of the forceps shank 2 in the outer shank 18, on actuation of the movable handle part 22.

[0030]FIG. 2 shows a detailed view of the forceps jaw 4 in the closed condition. FIG. 2 is a lateral view of the forceps jaw 4 in the direction of the arrow B in FIG. 1. The forceps jaw is formed by two jaw parts 26, 28. The two jaw parts 26 and 28 are formed spade or shell shaped so that together in the closed condition they likewise have an essentially tubular cross section. This means that the jaw parts 26 and 28 in the closed condition enclose a free space. The jaw parts 26 and 28 are rotatably mounted on two diametrally opposite sides in each case on a rotation point 30 on the outer shank 8. At the same time the jaw parts 26 and 28 on each side are in each case mounted in a common rotation point 30. Furthermore in the region of its distal end on the outer shank 8 there is formed a longitudinal groove 32 which extends in the longitudinal direction of the outer shank 8. In each case there is formed a longitudinal groove 32 on each of the diametrically opposite sides on which the rotation points 30 are also provided. Elongate projections 34 engage into these longitudinal grooves 32. The projections 34 extend likewise in the longitudinal direction of the forceps shank 2 or of the outer shank 8. The projections 34 are rigidly formed in the region of the distal end 14 of the inner shank 10 on this and extend from this radially outwards. The longitudinal grooves 32 in their longitudinal direction are formed longer than the projections 34 so that the projections are movable in the longitudinal grooves 32 in the longitudinal direction. In this manner the projections 34 and thus the inner shank 10 are guided in the longitudinal grooves with a movement in the longitudinal direction of the forceps shank 2. Furthermore the longitudinal grooves 32 have the effect that on rotation of the outer shank 8 via the hand wheel 11 the inner shank 10 is correspondingly co-rotated so that the complete forceps shank 2 with the forceps jaw 4 may be rotated with respect to the forceps housing 16 about the longitudinal axis of the forceps shank 2.

[0031]FIG. 3 shows a view of the forceps jaw 4 according to FIG. 2, wherein the forceps jaw 4 is opened. For opening the forceps jaw 4 the inner shank 10 in its longitudinal direction is displaced in the inside of the outer shank 8 in the distal direction. At the same time the projections 34 also displace in the longitudinal grooves. With a suitable dimensioning of the length of the longitudinal grooves and the corresponding projections 34 the end faces of the longitudinal grooves and the projections may serve as abutments for limiting the movement of the inner shank 10 in its longitudinal direction. A linkage point 36 is in each case formed on the projections 34. In total therefore there are provided two linkage points 36 on the two diametrically opposite sides of the forceps shank 2, on which the rotation points 30 are also arranged. The linkage points 36 in each case lie with one of the rotation points 30 on a common axis which extends parallel to the longitudinal axis of the forceps shank 2 on its side. On the linkage points 36 there are linked transmission levers 38 and 39 which pivot the jaw parts 26 and 28 about their rotation pints 30. Furthermore in FIG. 3 the maximal field of view S for optics arranged in the inside of the inner shank 10 is indicated. This field of view S extends proceeding from the distal end 14 of the inner shank 10. Such a large field of view S is made possible in that all mounting and actuation elements, i.e. the transmission levers 38, 30, the rotation points 30 as well as the linkage points 36 are arranged on two sides of the outer shank 8 diametrically opposite one another. This allows openings to be formed between these two opposite sides or side regions in the outer shank 8 which permit a correspondingly large field of view S.

[0032] The exact construction of the lever system for actuating the jaw parts 26 and 28 is explained in more detail by way of the schematic representation in FIG. 4. The view in FIG. 4 corresponds essentially to the view according to FIG. 2, the forceps jaw 4 is however shown sectioned in order to show the individual lever elements. The jaw parts 26 and 28 are shown in the closed condition. Since the jaw parts 26, 28 in each case are linked and mounted on two diametrically opposite sides of the forceps shank 2, all lever and actuation elements are formed in an identical manner on the two diametrically opposite sides of the forceps shank 2. For this reason hereinafter the design on one of the two sides is explained, the lever elements on the opposite side are designed identical. The projection 34 axially movable in the longitudinal direction of the forceps jaw 2 in the longitudinal groove 32 is rigidly connected to the inner shank 10 (not shown in FIG. 4). A linkage point 36 is formed on the projection 34. The two transmission levers 38 and 39 are pivotably linked or mounted on this linkage point 36. For this in each case there is provided a bore in the projection 34 and in the transmission levers 38, 39 through which there extends a rivet or bearing bolt. The transmission levers 38 and 39 are designed bent at an angle so that in the installed condition they are bent at an angle in two opposite directions to the longitudinal axis x or a plane through the longitudinal axis x and the rotation points 30. On ends of the transmission levers 38 and 39 which lie opposite the linkage points 36 there are provided rotation points 40 and 42 respectively. On account of the angled design of the transmission levers 38 and 39 the rotation points 40 and 42 lie outside the plane or axis which extends through the rotation points 30 and linkage points 36.

[0033] In the rotation points 40 and 42 the transmission levers 38 and 39 are rotatably connected to the jaw parts 26 and 28. This may likewise be achieved by bearing bolts or rivets which are applied into corresponding holes in the transmission levers 38, 39 and the jaw parts 26, 28. The jaw parts 26 and 28 comprise linkage levers 44 and 46. The linkage lever 44 is formed as one piece with the jaw part 26 and the linkage lever 46 as one piece with the jaw part 28. Proceeding from the associated jaw parts 26 and 28 the linkage levers 42 and 44 extend in the opposite direction, i.e. in the proximal direction of the forceps beyond the rotation point. At the same time the linkage levers 44 and 46 are bent at an angle with respect to the associated jaw parts 26 and 28 in a manner such that the jaw part 26 via the linkage lever 44 is linked on the rotation point on the side opposing or lying opposite the jaw part 26 with respect to the longitudinal axis x. Accordingly the jaw part 28 via the linkage lever 46 is linked on the rotation point 42 on the side which lies opposite the jaw part 28 with respect to the longitudinal axis x. In this manner one creates a parallelogram mechanism, wherein the rotation points 40 and 42 are distanced at a direction perpendicular to the x axis and from this axis. This has the effect that the connection lines between the rotation points 40 and 42 with the rotation point 30 as well as the linkage point 36 run at an angle to the rotational axis x. This ensures that with a movement of the linkage point 36 in the direction of the longitudinal axis in the distal direction, the two rotation points 40 and 42 are pressed apart by way of the transmission levers 36 and 39 so that they move away from one another. With this movement of the rotation points 40 and 42 the linkage levers 44 and 46 connected to these and thus likewise the associated jaw parts 26 and 28 are pivoted about the rotation point 30 so that the forceps jaw 4 opens. The movement of the linkage point 36 in the longitudinal direction x is effected by a movement of the inner shank 10 in its longitudinal direction since the inner shank 10 is rigidly connected to the projection 34.

[0034]FIG. 5 shows a section view of the forceps jaw according to FIG. 4 in the direction of the arrows A in FIG. 4. The distal end region 48 of the outer shank 8, on two diametrically opposite sides, forms in each case a receiver gap 50 in which the linkage and transmission levers 44, 46 and 38 and 39 respectively are arranged. The levers are arranged lying over one another or overlapping, in a manner such that the transmission lever 39 on one of the sides lying diametrically opposite lies radially further inwards with respect to the longitudinal axis x than on the opposite side. Accordingly the associated linkage levers on one side are arranged lying further radially inwards than on the other side. Thus the linkage and transmission levers 38, 39, 44 and 46 form an extremely flat parallelogram mechanism which is arranged in the respective receiver gap 50. For its design also in each case one of the linkage levers 44 or 46 on the jaw parts 26 and 28 on the one side are situated lying further inwards to the longitudinal axis x than the diametrically opposed side. On the side at which the linkage lever 46 lies further outwards, the associated transmission lever 39 lies further inwards and on the side on which the linkage lever 46 lies further inwards, the associated transmission lever 39 lies further outwards. This correspondingly applies to the linkage levers 44 of the jaw part 26 and the associated transmission levers 38. The linkage levers 44, 46 and transmission levers 38, 39 are in each case arranged parallel to one another and lying over one another or overlapping in the receiver gaps 50.

[0035]FIG. 6 shows a view according to FIG. 4 with which the forceps jaw 4 is opened. As already explained by way of FIG. 4, for opening the forceps jaw 4 the inner shank 10 (not shown in FIG. 6) in the inside of the outer shank 8 is moved along the longitudinal axis in the direction of the distal end of the forceps, i.e. in the direction of the forceps jaw 4. At the same time on each of the diametrically opposite sides the projection 34 with the linkage point 36 likewise moves in the direction of the distal end. By way of this on each side the transmission levers 38 and 39 are pressed outwards so that the rotation points 40 and 42 move away from one another. Since the linkage levers 44 and 46 at the rotation points 40 and 42 are rotatably connected to the transmission levers, with this movement the linkage levers 44 and 46 are rotated about the respective rotation point 30. At the same time the jaw parts 26 and 28 are likewise rotated about both rotation points 30 so that the forceps jaw opens 4.

[0036]FIG. 7 shows an individual view of a jaw part 26. The jaw part 28 is designed identically to the jaw part 26. The jaw part 26 is shell-shaped, wherein at the lowest point there is formed an opening 52. The opening 52 permits one to observe the region of the surroundings of the forceps jaw 4 through the inside of the forceps through the hole when the forceps jaw is closed. The linkage levers 44 extend in the proximal direction at the distal end of the jaw part 26. The linkage levers 44 extend parallel to the longitudinal axis x. In the linkage levers 44 there are formed suitable bores for the rotation points 30 and 42 for connecting to the outer shank 8 and the transmission levers 39. The two linkage levers 44 are formed on two diametrically opposite sides of the jaw part 26. At the same time on one side the linkage lever 44a lies further inside, i.e. closer to the longitudinal axis x than the linkage lever 44 b on the diametrically opposite side. This formation permits the displaced overlapping arrangement of linkage and transmission levers. The transmission levers 46 on the second jaw part 28 are designed identically.

[0037]FIG. 8 shows a section view of the jaw part 26 according to FIG. 7 along line 1-1 in FIG. 7. In FIG. 8 the shell-shaped design of the jaw part 26 can be seen, wherein the opening 52 is arranged at the lowest point, i.e. at that point which lies farthest from the middle axis of the forceps shank 2. The linkage lever 44 or 44 b is designed bent at an angle to the jaw part 26 so that the rotation point 42 is distanced further radially from the outer side 54 of the jaw part 26 than the rotation point 30. This permits the two jaw parts 26 and 28 to be arranged over one another in a manner such that they are rotatable about the same common rotation point 30 and cross over the two linkage levers 44 and 46. In this manner one may create the parallelogram mechanism explained by way of FIG. 4 which permits a secure actuation of the forceps jaw 4 without danger of any jamming.

[0038]FIG. 9 shows a detailed view of a transmission lever 39. The transmission lever 38 at one end comprises an opening or bore for the rotation point 40 and at the opposite end a hole or a bore for the linkage point 36. Bearing and joint bolts or rivets may extend through these holes. The linkage lever 38 has a bent configuration as is explained by way of FIG. 4.

[0039] As a whole the medical forceps according to the invention has an extremely slim arrangement of all mounting and actuation elements for the forceps jaw 4 on two diametrically opposite sides of the forceps shank 2. In particular the actuation elements, i.e. the linkage levers 44, 46 and the transmission levers are in each case arranged in the same circumferential region as the rotation points 30 on which the jaw parts 26 and 28 are mounted. In this manner the circumferential regions which are required for mounting and linkage of the jaw parts 26 and 28 on the forceps shank 2 may be designed very slimline so that in the remaining circumferential region the field of view S of optics 12 arranged in the forceps shank is not limited. Furthermore the linkage of the jaw parts on both sides permits the production of a large clamping force of the forceps, wherein both jaw parts 26, 28 are led in a torsionally stiff manner.

LIST OF REFERENCE NUMERALS

[0040]2—forceps shank

[0041]4—forceps jaw

[0042]6—handle

[0043]8—outer shank

[0044]10—inner shank

[0045]11—hand wheel

[0046]12—optics

[0047]14—distal end of the inner shank

[0048]16—forceps housing

[0049]18—cone connection

[0050]20—displacement sleeve

[0051]22—moveable handle part

[0052]24—rigid handle part

[0053]26,28—jaw part

[0054]30—rotation point

[0055]32—longitudinal groove

[0056]34—projection

[0057]36—linkage point

[0058]38,30—transmission lever

[0059]40,42—rotation points

[0060]44, 46—linkage levers

[0061]48—distal end region of the outer shank

[0062]50—receiver gap

[0063]52—opening

[0064]54—outer side 

1. A medical forceps with a tubular outer shank on whose distal end there is formed a forceps jaw with two jaw parts, wherein the two jaw parts are rotatably mounted on the outer shank in each case on two sides opposite one another, with a tubular inner shank for actuating the jaw parts, which is displaceably arranged in the inside of the outer shank in its longitudinal diecrion x, wherein the inner shank is coupled to the two jaw parts for their actuation via two lever systems and in each case one of the lever systems is linked on the two jaw parts on one of the two sides opposite one another.
 2. A medical forceps according to claim 1, with which the two jaw parts in each case on each of the two sides opposite one another comprise linkage levers which extend proximally in the longitudinal direction of the outer and inner shank and which in each case are connected to the inner shank via one of the two lever systems.
 3. A medical forceps according to claim 2, with which the linkage levers and the lever system are arranged lying further radially outwards than the inner circumference of the inner shank.
 4. A medical forceps according to one of the preceding claims, with which the two jaw parts on the two sides opposite one another in each case are mounted on a common rotation point on the outer shank.
 5. A medical forceps according to one of the preceding claims, with which the linkage levers in each case are connected to the inner shank via a transmission lever.
 6. A medical forceps according to claim 5, with which the transmission levers in each case at a first end are rotatably connected to a linkage lever and at a second end to the inner shank.
 7. A medical forceps according to claim 6, with which at the sides of the inner shank opposite one another in each case two transmission levers in a common rotation point are connected to the inner shank.
 8. A medical forceps according to one of the preceding claims, with which at the distal end of the inner shank there is formed at least one radially outwardly projecting projection which engages into a corresponding recess at the distal end of the outer shank, wherein the recess in the longitudinal direction of the outer and of the inner shank has a greater extension than the projection.
 9. A medical forceps according to claim 8, with which on the inner shank there is formed in each case one projection on each of the two sides opposite one another and the outer shank comprises two corresponding recesses at each of the sides opposite one another, into which the projections engage.
 10. A medical forceps according to one of the preceding claims, with which the linkage levers of the two jaw parts on each of the two sides opposite one another are designed in a manner such that the linkage lever of the first jaw part is designed lying radially further inwards than the linkage lever of the second jaw part.
 11. A medical forceps according to one of the claims 5 to 9, with which the two transmission levers on each of the sides opposite one another in each case are arranged lying radially over one another.
 12. A medical forceps according to one of the preceding claims, with which the linkage levers of the two jaw parts on each of the two sides opposite one another are designed in a manner such that seen in the longitudinal direction of the outer shank in the closed condition of the forceps jaw the free end of the linkage lever of the first jaw part extends in the extension of the second jaw part and the free end of the linkage lever of the second jaw part extends in the extension of the first jaw part.
 13. A medical forceps according to one of the preceding claims, with which a hole is formed in at least one of the two jaw parts. 